The present invention relates to a member for an internal combustion engine, and a piston, a valve, and a fuel injection valve using the member, and a production or manufacturing method of the member for internal combustion engine, and more particularly, a member for an internal combustion engine capable of suppressing deposit, and a piston, a valve, and a fuel injection valve using the member, and a production or manufacturing method of the member for an internal combustion engine.
A so-called deposit is formed on components in a combustion chamber of an internal combustion engine owing to incomplete combustion of fuel. The deposit is a strongly adhesive substance including a mixture of a carbonized matter of the fuel (carbon contents) and a gummy matter of oxidized fuel, and deposits within the combustion chamber, causing deterioration in performance in fuel consumption or exhaust, which has been a problem.
For example, when deposit exists on a crown surface of a piston or a surface of a valve, the fuel becomes wettable and adheres thereto, reducing combustion efficiency of the fuel and therefore increasing unburned hydrocarbon contained in exhaust gas.
To prevent such adhesion of deposit, for example, a fluororesin coating on an inner wall surface of the combustion chamber or an inner wall surfaces of a cylinder head and a piston head, and wall surfaces of the piston head and an intake valve has been proposed in patent literatures JP-UM-A-62-137360, JP-UM-A-62-154250 and JP-A-2-176148.
In particular, in the case of a fuel injection valve of an in-cylinder direct injection engine, since dimensional accuracy of a component is strict, deposition of the deposit on the periphery of a fuel injection hole causes a clogged nozzle opening or deterioration in fuel spray control, which has been a problem.
As measures for preventing such adhesion of the deposit to the injection hole, a nozzle provided with the fluorine-resin coating or a nozzle supplied with dispersion plating using PTFE (polytetrafluoroethylene) particles have been known from patent literatures JP-UM-A-59-84274 and JP-A-10-89199.